Thread chaser



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THREAD CHAS ER Filed Feb. 28. 1929 Hum H52 1H Hill Mix

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25., IMWK Patented May 10, 1932 UNITED STATES PATENT ()FFKTE WIL IAM r. n. oAMrAIGNnor sroonnn, Wisconsin 7 I I THREAD cIrAsEn I Application filed February 28,1929. Seria1 No.-343,389 I The object of the invention is to provide the block 11 in a hole bored through the side a tool for the restoration of damaged threads of the block and entering the tool slot, so that in bolts or pipe and rotatable,'without any the screw may bear upon the cutter and "-readjustment, to clean or renew the threads tain it in position after it has been adjusted whether they be right-hand or left-hand; to to extend into its proper position in the openprovide a tool in which the cutter may be fed ing 12. r

' to the threads by hand during the operation In the operation of the device, the nuts 16 of truing the same; and to provide a tool are rotated to permit separation of the blocks which consists of but few parts and is there- 11 and and the screw or pipe with the dam- 19 fore of simple form and susceptible of cheap aged threads is inserted through the open- 60 manufacture d l k ti t, mg 12, the cutter bein seated between two With this object in View the invention conadjacent threads, preferably those which sists in a construction and combination of have not been marred. The nuts 16 are then parts of which a preferred embodiment is rotated to bring those sides of the Opening 1. illustrated in the accompanying drawings, 12 in the block 10 into contact with the screw h i and thejtool then is rotated, the cutter 18 Figure 1 is an elevational view showing trulng the threads as the tool is advanced the invention applied as a chaser or truing therealong. If the thread to be trued be leftt l on th thr d of a cap screw. .1 hand, it is placed'on the work in the opposite Figures 2 and 3 are sectional views on the direction than where the thread be rightplanes indicated by the lines 2-2 and 33 handthat is the work enters the tool from respectively of Figure 1. the opposite face in the one case from where The invention consists of the clamp block It does in the other. The cutter may be in: 10 and cutter block 11 in the two of which is itlally adjusted to cut the full depth of thread i formed a polygonal opening 12 which, in the but the initial operation need be only to take 75 illustrated embodiment, is square. The a light out, increasing the cuts on succeeding opening is formed by recessing the two blocks operations by the adjustment towards each on their contacting edges and the diagonal other of the two blocks through the tightenof tlie opening is coincident with said con- 111g of the nuts 16. By this plan, the block tacting edges. The two blocks are adj ust- 10 will always hear on the work but the block ably secured together by means of studs 14 11 will remain out of contact with the latter which are secured to the block 10, preferably until the full depth of cut is accomplished. by threads as indicated at 15, and these studs By reason of the position of the cutter 17 extend through openings in the block 11, rein the block 11, one corner of the lower end 7 j ceiving on their upper threaded ends the constitutes the cutting edge and if this should 85 knurled nuts 16 by means of which the two become dull by constant use, the cutter may I may be clamped on a bolt or pipe inserted be withdrawn and turned 180 on its longithrough the opening 12. tudinal axis when the, opposite edge of its The cutter 17 which is preferably formed lower end becomes a cutting edge. Thus the of high speed steel is adjustably mounted in two edges may be used before sharpening of a cross-sectionally polygonal slot in the block the cutter becomes necessary. 11, the slot conforming to the cross-sectional The inventionhaving been described what contour of the cutter, and the cutting edge 18 is claimedas new and useful is: of the latter which is formedto'conform to A thread chaser consisting of a pair of the angle of the threads to be operated upon blocks, studs carried in the edge of one block invades that part of the opening 12 in the and extending through holes in the other to block 11, one face of the cutter lying in the bring the two into edge facing position, each diagonal line of the opening at right angles block being recessed on its face contacting to the line of contact between the two blocks. with the other to provide a polygonal open- A set screw 19 is threadingly mounted ining existing half in one and half in theother,

spondingly shaped slot formed in the block nuts engaged with the studs and bearing on the block having sliding enga ement with the studs, and a cutter carried y the latter block and invading the opening defined by the two, the cutter being cross-sectionally polygonal and extending through a c0rre by which it is carried, and a set screw threadingly engaged with said block and bearing upon the cutter to maintain the adjustment of the latter, the stud oar-rying block bearing on the work but the cutter-carrying block belng held by the cutter out of contact with the work until the fulldepth of cutis accom- 'plished by the repeated adjustment of said" nuts.- 7

- lngtest-imony ture. in

' WILLIAMT. n. OAMPAIGNEQ whereof he. afiixeshis signa- 

